ABSTRACT
Aim To construct TLR9 gene knockout mouse model and preliminarily identify the phenotypes. Methods The TLR9 knockout mice were established by CRISPR/Cas9 system. The genotype of knockout mice was identified by capillary gel electrophoresis, while the PCR product was sequenced to analyse the knockout efficiency. The mRNA and protein expression level of TLR9 were determined by qRT-PCR, Western blot and immunohistochemistry. Genetic traits, body weight and blood routine changes were also measured. Pathological changes of mouse tissues were observed by hematoxylin-eosin (HE) staining. Results PCR and sequencing results showed that the stable TLR9 gene knockout mice were generated. The TLR9 gene expres-sions of knockout mice in spleen and liver tissues were significantly lower than those of wild-type mice. The growth and breeding of TLR9 knockout mice were normal , as well as all indexes of body weight and peripheral blood routine. The histomorphological characteristics of TLR9 knockout mice showed no significant difference compare to wild-type mice. Conclusions The TLR9 knockout mice are successfully established, providing an experimental animal model for studying the biological functions and regulatory mechanisms of the TLR9.